1. Field of the Invention
This invention relates to a staple-type fastener adapted to be arranged in multiple numbers in a connected series to form a cartridge and driven individually into engagement with an article to be fastened, and more particularly relates to such a staple-type fastener in which the legs or members that penetrate the article to be fastened penetrate at an angle, with the exposed ends of such legs being interconnected by overlapping webs movable relative to each other as the fastener is driven and interlockable when the fastener reaches its final position.
2. Description of the Prior Art
A search of the prior art has been made in Class 85, sub-classes 11, 13, 17, 23, 26, 38 and 49; and in Class 52, sub-class 543. As a result of such search, U.S. Pat. Nos. 2,132,259; 3,618,447; 3,788,187 and 3,885,491 have been found. All of these prior art patents relate to staple-type fastener devices but are distinguished from the subject matter of this invention in that they do not incorporate penetration members or legs that move toward each other during insertion and which are interconnected by relatively movable and interlocking webs.
Conventional staples that are used in industry with greater frequency possess the disadvantage that they tend to work loose and are readily disengaged, thus loosening whatever they are intended to secure. For instance, it is common practice to utilize generally U-shaped staples to attach red-cedar shingles in a roof structure. It has been found that as soon as the wood into which they are driven loses its resilience, generally through drying, there is a tendency for such staples to loosen in the furring strips through which they are driven, thus resulting in shingles being lifted from the roof by wind action.
Attempts have been made to obviate this disadvantage as indicated in U.S. Pat. No. 3,618,447 by providing barbs on the lebgs of the staple or, as indicated in U.S. Pat. No. 3,788,187 by causing the legs of the staple to diverge and move away from each other as they penetrate the wood. Accordingly, one of the objects of this invention is to provide a composite staple-like fastener possessing legs for penetration of an article to be fastened that move toward each other as the staple is driven and the upper ends of which legs are interconnected by interlocking webs that also simultaneously move relative to each other as the fastener is driven.
In a monolithic conventional staple-like fastener that has parallel legs driven straight into an article to be fastened there is no need for a connecting web comprised of relative movable portions. This distinction is also not necessary in a staple such as the one indicated in U.S. Pat. No. 3,788,187 in which the points of penetration of the legs are equally spaced with the opposite ends of the legs. However, in a fastener of the type forming the subject matter of this invention, where the points of penetration of the fastener legs are spaced closer together than the opposite ends of the legs, and which move even closer toward each other when driven, it is necessary that means be provided to accommodate the decrease in spacing between the upper ends of the legs while maintaining an interconnection between such legs. Accordingly, a still further object of the invention is the provision in a composite staple-type fastener having converging leg portions interengaging connecting web portions that move relative to each other when the staple is driven.
A still further object of the invention is the provision of a staple-like fastener incorporating spaced legs adapted to be driven into an article to be fastened, each of the legs having on one end a transversely extending web portion. slidably overlapping the corresponding web of the opposite leg and including locking lugs adapted to interengage to retain the webs in interlocked condition when driving of the composite staple-like fastener has been completed.
Another object of the invention is the provision of a driving structure including a housing for containing a multiplicity of the staple-like fasteners arranged in cartridge form prior to driving and which during the driving process forces the fastener legs of an individual fastener to move toward each other to achieve an ultimate interlocked condition.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described since it may be embodied in various forms within the scope of the appended claims.